Which carbocation, formed due to ionisation of the C-Cl bond will be more stable between 2-chloro-2-methylpropane or chloromethyl benzene and why?

At first I thought it should be the 2-chloro-2-methylpropane because from what I know methyl groupss are electron donating groups and benzene rings are almost always electron withdrawing groups, thus the methyl groups will help stabilize the carbocation more. But apparently it is the carbocation of the chloromethyl benzene that'll be more stable and I really can't understand why that is? I've searched a couple of other sites and gone through my book as well but it doesn't quite explain this.

I tried to upload the images but it would just not let me, so I'll try my best to explain them here. On the 2-chloro-2-methylpropane the carbocation I'm referring to is the one forming on the central carbon atom and on the chloromethyl benzene its the one on the carbon atom of the methyl group. Hope that makes it clear; both are formed due to losing ionisation of the $\ce{C-Cl}$ bond.